So since this is a new account I can't post a direct link, but if you were to go to, say, Empty Beer at: http://reviews[dot]mtbr[dot]com/ibis-mojo-3-first-ride-review you can find a nice little write-up of the new Mojo 3. Peanut Butter also has a review at http://www[dot]pinkbike[dot]com/news/ibis-mojo-3-review[dot]html
Geometry, suspension, ride report aside, there are some very interesting little gems from Ibis:
From Empty Beer:
"Ibis believes there is a sweet spot with plus size tires, and 2.8” width is it. They found that beyond this size, plus tires tend to get bouncy and heavy, or as Ibis engineer Colin Hughes puts it, “Plus size tires are really fun…until they’re not.”"
From Peanut Butter:
"The Mojo 3 is pictured here with 2.8'' wide tires from Schwalbe, and that's also the configuration that I spent most of my time on, but Ibis' Scot Nicol does stress that the new bike is far from being a plus-only machine. ''We’ve found that the [width] numbers printed on tire sidewalls mean very little when it comes to their height,'' Nicol explained after experimenting with just how much of a difference there is in diameter between plus and standard 27.5'' tires. ''The Schwalbe and Maxxis 2.8s are only 0.15” taller in section height than a 2.3'' tire, whereas 3.0'' tires are 0.4” taller. "
Okay, so basically we have Ibis, who certain bikes aside, generally knows what they're doing flat out saying taller sidewalls suck, and the biggest plus size tire you should be running is a 2.8". Which makes sense from an engineering standpoint.
But here's the rub- in every single one of the (many, ad naseum) plus size reviews that are trying to shove new crappy bikes down our throats, someone always mentions traction and stability as the biggest benefits. The traction comes from the ~13-17 psi you run in a plus size tire, which gives you a huge contact patch. The stability comes from a wide rim that can support the sidewall of the tire better. Okay, to a point I will agree with that.
The downside of this traction and stability is weak, tall side walls that will fold under hard cornering and provide a terrible, spikey suspension input that is almost impossible to damp out. Basically if you're going to hit a rock garden at race speed on a plus bike, your health coverage better be good.
But here's the thing- we already have existing, normal, non-obese components that can do this. Take the WTB i35 rim with a Minion DHRII WT casing set up with Procore. Now you have a nice, wide rim (and a tire designed for it!), with actually beefy as hell cornering nobs, and you have the ability to drop the pressure to the same level you run plus tires at. Since you're running the same pressure, you have the same contact patch and the same traction. Actually, you have better traction because you don't have to half-ass the nobs in the name of saving weight. Also, you have a nice, stable, supported sidewall that has the extra help of procore keeping it in place. Finally, when shit gets gnarly, you will actually be getting better performance out of your tires (procore was designed for WC DH remember), and your suspension will be operating better as well. And the best part is you can do all of this on the bike you already own.
So, what am I missing? Is there some inherent advantage to wider tires that isn't lower pressures or supported sidewalls? Because we can do that already. Now we just need tire makers to go the "normal tires for wide rims" route that Maxxis started for trail and XC-ish tires, not just beefier AM and DH casings- the weight difference between a 2.35 Nobby Nic 650b and the 2.8 Nobby Nic 650b+ just so happens to be almost exactly the weight of a procore insert. So why not get rid of this plus size nonsense and just run better regular tire systems?
Geometry, suspension, ride report aside, there are some very interesting little gems from Ibis:
From Empty Beer:
"Ibis believes there is a sweet spot with plus size tires, and 2.8” width is it. They found that beyond this size, plus tires tend to get bouncy and heavy, or as Ibis engineer Colin Hughes puts it, “Plus size tires are really fun…until they’re not.”"
From Peanut Butter:
"The Mojo 3 is pictured here with 2.8'' wide tires from Schwalbe, and that's also the configuration that I spent most of my time on, but Ibis' Scot Nicol does stress that the new bike is far from being a plus-only machine. ''We’ve found that the [width] numbers printed on tire sidewalls mean very little when it comes to their height,'' Nicol explained after experimenting with just how much of a difference there is in diameter between plus and standard 27.5'' tires. ''The Schwalbe and Maxxis 2.8s are only 0.15” taller in section height than a 2.3'' tire, whereas 3.0'' tires are 0.4” taller. "
Okay, so basically we have Ibis, who certain bikes aside, generally knows what they're doing flat out saying taller sidewalls suck, and the biggest plus size tire you should be running is a 2.8". Which makes sense from an engineering standpoint.
But here's the rub- in every single one of the (many, ad naseum) plus size reviews that are trying to shove new crappy bikes down our throats, someone always mentions traction and stability as the biggest benefits. The traction comes from the ~13-17 psi you run in a plus size tire, which gives you a huge contact patch. The stability comes from a wide rim that can support the sidewall of the tire better. Okay, to a point I will agree with that.
The downside of this traction and stability is weak, tall side walls that will fold under hard cornering and provide a terrible, spikey suspension input that is almost impossible to damp out. Basically if you're going to hit a rock garden at race speed on a plus bike, your health coverage better be good.
But here's the thing- we already have existing, normal, non-obese components that can do this. Take the WTB i35 rim with a Minion DHRII WT casing set up with Procore. Now you have a nice, wide rim (and a tire designed for it!), with actually beefy as hell cornering nobs, and you have the ability to drop the pressure to the same level you run plus tires at. Since you're running the same pressure, you have the same contact patch and the same traction. Actually, you have better traction because you don't have to half-ass the nobs in the name of saving weight. Also, you have a nice, stable, supported sidewall that has the extra help of procore keeping it in place. Finally, when shit gets gnarly, you will actually be getting better performance out of your tires (procore was designed for WC DH remember), and your suspension will be operating better as well. And the best part is you can do all of this on the bike you already own.
So, what am I missing? Is there some inherent advantage to wider tires that isn't lower pressures or supported sidewalls? Because we can do that already. Now we just need tire makers to go the "normal tires for wide rims" route that Maxxis started for trail and XC-ish tires, not just beefier AM and DH casings- the weight difference between a 2.35 Nobby Nic 650b and the 2.8 Nobby Nic 650b+ just so happens to be almost exactly the weight of a procore insert. So why not get rid of this plus size nonsense and just run better regular tire systems?